Description:I will give an overview of 5 (clearly connected)
appearances of ``positive geometries" in physics: (1) the
amplituhedron and N=4 SYM, (2) the associahedron and general massless
theories in D dimensions, (3) cosmological polytopes, and
work-in-progress on (4) the positive geometry of effective field
theory (a big generalization of ``positive signs" for operators--where
higher dimension operator coefficients are seen to be constrained to
live inside "UV/IR polytopes"), and (5) the positive geometry of
conformal field theory (which underlies the bootstrap). (2:00 PM, 726 Broadway, 940, CCPP Seminar)